JP2002338237A - Mold agent, method for producing mesoporous material using the mold agent and mesoporous material obtained by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a mesoporous material which has a fine pore size of >=20 Åby using a polyoxyethylene alkylamine as a mold agent. SOLUTION: Polyoxyethylene laurylmine (C12 H25 -NH-(EtO)5 ) of 10.1 g (0.025 mol) is dissolved in a mixed solvent of water of 135 g (7.49 mol) and ethanol of 47.0 g (1.00 mol) at a room temperature, and tetraethyl orthosilicate of 15.62 g (0.075 mol) is added thereto. This mixture is stirred at a room temperature for 48 hr. After that, the solid component is taken by filtering, is water-washed, and is dried at 40 deg.C for 60 hr to obtain the solid component (mesoporous material containing the mold agent) of 8.84 g.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a mesoporous substance which is useful in the fields of material chemistry, catalytic chemistry, surface chemistry, organic synthetic chemistry and the like by using a novel template, said template, And the resulting mesoporous material.

[0002] Microporous materials such as zeolites have regular spaces (pores) in the structure and are used for various purposes such as heterogeneous catalysts, adsorbents, ion exchange agents, soil conditioners and the like. ing. In recent years, large-diameter zeolites having a larger pore diameter have been developed in order to enhance the function of the zeolite, but the pore diameter was still 20 Å or less.

[0003]

2. Description of the Related Art Mobil Res. & Dev.
A quaternary ammonium salt having a long carbon chain (for example, nC
₁₆ using the _{H 33 -N (CH 3) 3} Cl) as templating agent, in an alkaline aqueous solution, for the first time synthesized a series of mesoporous materials (M41S named) having the ordered structure (Natu
re, 359 , 710-712 (1992)), and thereafter, research in this field has been actively conducted. Such mesoporous materials are:
The structure has regular pores (20 to 40 angstroms) in the meso region in the structure, shows a characteristic X-ray diffraction pattern reflecting the structure, and is used as an adsorbent or a catalyst. Further, the pore diameter can be adjusted by the molecular length of the template used during the synthesis.

[0004] Other than the above Mobil mold agent,
Alkylamine (R-NH₂) (Science,267, 865 (1
995)) and alkyl polyethylene oxide (R- (Et
O) _n) (Science,269, 1,242 (1995)), polyethylene
Polypropylene triblock oxide ((EtO)
_n-(PO)_m-(EtO)_n) (Science,279, 548
(1998)) and other non-ionic surfactants
Used for synthesis of soporous nature.

[0005]

[SUMMARY OF THE INVENTION However, among the templating agent, quaternary ammonium salts (e.g., n-C ₁₆ H ₃₃
—N (CH ₃ ) ₃ Cl) is expensive and harmful, and the synthesis of mesoporous materials using it requires pressurized conditions, usually using an autoclave. Also,
Since this salt is an ionic substance and ion-bonds with the mesoporous property generated under hydrothermal conditions, there was a problem that the template agent could not be removed from the conjugate by solvent extraction.

[0006] On the other hand, higher alkylamines have poor hydrophilicity and are therefore incompatible with water. Although alkyl polyethylene oxide and polyethylene polypropylene triblock oxide are inexpensive and excellent in safety, they require strongly acidic conditions when used, and the surface area and pore volume of the produced mesoporous material are significantly reduced. Its performance as an agent is inferior to quaternary ammonium salts.

[0007] An object of the present invention is to solve all of the above-mentioned problems, to be inexpensive, highly safe and hydrophilic.
Provide a template agent capable of performing a reaction under mild conditions, removing a template agent by solvent extraction, and obtaining a mesoporous material having a high surface area of 20 Å or more in pore size and a large pore volume. Is to do.

[0008]

The template for producing a mesoporous material according to the present invention has a general formula: R ¹ —NH— (EtO) _n ... [I] (wherein R ¹ is a carbon atom 8-36 alkyl groups.
(EtO) _n is a polyethylene oxide chain, and n is an integer of 2 to 200. )).

[0009] The present invention also provides a method for producing a mesoporous substance, which produces a mesoporous substance using the above-mentioned template [I].

Specifically, using the above-mentioned template [I],
General formula: (R¹-NH- (EtO)_n)_r1R² _r2M_m(A_aB_bC_cD_dE_eF _f G_gO_x(II) (where A is a divalent element (for example, Co, Cu, Zn
A) is its coefficient 0-1. B is a trivalent element
(For example, Al, Ga, Fe, etc.), and b has a coefficient of 0
0.67. C is a tetravalent element (for example, Si, Ti
And c is its coefficient 0 to 0.5. D is a pentavalent element
(E.g., P), and d is a coefficient between 0 and 0.4.
You. E is a hexavalent element (for example, Cr, W, etc.) and e is
0 to 0.33. F is a heptavalent element (eg, M
o, etc.), and f is its coefficient 0 to 0.29. G is 8
Is a valence element (for example, Os), and g has a coefficient of 0 to 0.
25. O is an oxygen atom, and x is its coefficient 1.
However, all of the coefficients a, b, c, d, e, f and g are
They cannot be zero at the same time. M is a hydrogen atom, an alka
Metal (eg, Na, K, etc.), alkaline earth metal (eg,
For example, Mg, Ca, etc.) and rare earth metals (eg, La,
Ce), at least one selected from the group consisting of
m is the coefficient 0.001-2. M is selected from the above group
If there are multiple types,_mIs M¹ _m1, M² _m2,
M³ _m3… (M¹, M², M³… Is selected from the above group
With multiple species,_m1,_m2,_m3… Is their coefficient 0.00
1 to 2). R¹-NH- (Et
O)_nIs the template according to the invention contained in structure [II]
In part, r1 is its coefficient 0.01-1. That is,
R¹Is an alkyl group having 8 to 36 carbon atoms. (EtO)
_nIs a polyethylene oxide chain, and n is an integer of 2 to 200
It is. R²Are the above elements A to G (these are collectively referred to as Z)
) And a Z-carbon bond or a Z-oxygen-carbon bond
Linking organic groups (eg, methyl, ethyl, vinyl,
Phenyl group), and r2 has a coefficient of 0 to 1. )
To produce a template-containing mesoporous material represented by
it can.

A preferred example of the mesoporous material containing a template is represented by the following general formula: (R ¹ -NH- (EtO) _n ) _r1 R ² _r2 M _m (Al
_b Si _c O _x ) wherein M is a hydrogen atom and / or an alkali metal;
¹ , (EtO) _n , n, r1, R ² , r2, m, b, c
And x are the same as above. However, the coefficients b and c are never zero at the same time. ).

The template is removed by subjecting the mesoporous material containing the template to high-temperature firing, solvent extraction, or the like. The template extracted into the solvent is recovered and reused.

[0013] mesoporous material after excluding the templating agent, the general ^{_{formula: R 2 r2 M m (A}} a B b C c D d E e F f G g O x) ......... ...... [III] ( In the formula, A is a divalent element (eg, Co, Cu, Zn, etc.), a has a coefficient of 0 to 1. B is a trivalent element (eg, Al, Ga, Fe, etc.), and b is the trivalent element. Coefficient 0
0.67. C is a tetravalent element (for example, Si, Ti, etc.), and c has a coefficient of 0 to 0.5. D is a pentavalent element (for example, P), and d has a coefficient of 0 to 0.4. E is a hexavalent element (for example, Cr, W, etc.), and e has a coefficient of 0 to 0.33. F is a heptavalent element (eg, M
o, etc.), and f is its coefficient 0 to 0.29. G is 8
Is a valence element (for example, Os), and g has a coefficient of 0 to 0.
25. O is an oxygen atom, and x is its coefficient 1.
However, all of the coefficients a, b, c, d, e, f, and g are not simultaneously zero. M represents a hydrogen atom, an alkali metal (eg, Na, K, etc.), an alkaline earth metal (eg, Mg, Ca, etc.) and a rare earth metal (eg, La,
Ce), at least one selected from the group consisting of
m is the coefficient 0.001-2. When M is a plurality of species selected from the above group, M _m is M ¹ _{m 1} , M ² _m ² ,
^{_{M 3 m3 ... (M 1,}} M 2, M 3 ... in multiple species selected from the above _{group, m1, m2, m3 ...} are the coefficients 0.00
1 to 2). R ² is the above element (Z)
And an organic group (for example, a methyl, ethyl, vinyl, phenyl group or the like) linked by a Z-carbon bond or a Z-oxygen-carbon bond, and r2 has a coefficient of 0 to 1. ).

[0014] Of the two mold agent removing method described above, in the method according to the firing, the formula coefficient r2 of R ² in [III] is zero, R ² in the general formula [III] in the process according to solvent extraction
Is kept as it is even after the extraction.

[0015] Preferred examples of mesoporous material after removing the templating agent has the general ^{_{formula; R 2 r2 M m (Al}} b Si c O x) ( wherein, M represents a hydrogen atom and / or an alkali metal, R
² , r2, m, b, c and x are the same as above. However,
The coefficients b and c are never zero at the same time. ) Is a mesoporous substance represented by

The mesoporous material according to the present invention has a pore size of 2
It has a high surface area and a large pore volume of 0-200 angstroms.

Next, a method for producing a mesoporous substance using polyoxyethylene alkylamine as a template agent will be described.
Give an explanation.

The mesoporous substance is a template comprising the starting compound (Q) and polyoxyethylene alkylamine [I].
It is prepared by mixing (L) in a solvent (S) while adjusting the pH and reacting.

The mixed composition of the starting compound (Q) and the template (L) is represented as follows.

The Q / L molar ratio is preferably 0.1 to 10
0, more preferably 1 to 10.

The S / L molar ratio is preferably from 0.1 to 50.
00, more preferably 50 to 1,000.

Here, Q is the total number of moles of the element (Z) from the divalent element A to the octavalent element G.

When the mesoporous material contains an organic group R ² , the R ² / Q molar ratio is between 0 and 1, preferably between 0.1 and 1.
0.5.

The starting compound (Q) is an alkoxy compound of the element (Z) from a divalent element A to an octavalent element G, an oxide,
It may be a sulfide, a hydroxide, a haloken compound, an inorganic acid salt, an organic acid salt, or the like.

In the polyoxyethylene alkylamine represented by the general formula: R ¹ —NH— (EtO) _n ... [I], R ¹ is an alkyl group having 8 to 36 carbon atoms. (Et
O) _n is a polyethylene oxide chain, and n is an integer of 2 to 2
00. By the combination of R ¹ and n, R ¹ —NH—
(EtO) The hydrophilic-hydrophobic balance of _n can be adjusted. Polyoxyethylene alkylamine [I] may be used alone or in combination of two or more.

The solvent (S) is composed of the starting compound (Q) and the template (L).
Are preferable, and those containing at least one hydrogen bond are preferable, and examples thereof include water, alcohols, amines, and mixtures thereof. Preferred alcohols are monohydric alcohols and polyhydric alcohols having 1 to 6 carbon atoms, and preferred amines are primary alkylamines, secondary alkylamines and tertiary alkylamines having 1 to 6 carbon atoms.

The reaction temperature is preferably from -50 ° C to 200 ° C.
° C, more preferably 20 ° C to 100 ° C. The reaction time is preferably 5 minutes to 200 hours, more preferably 1 hour to 50 hours.

Examples of the pH adjusting agent used for adjusting the pH of the reaction solution include inorganic acids (eg, hydrochloric acid, sulfuric acid, nitric acid, etc.), organic acids (eg, formic acid, acetic acid, etc.), and inorganic alkalis (eg, aqueous ammonia, NaOH, etc.). KOH), organic alkali (amine, pyridine, etc.) and the like.

A slurry is prepared by mixing the starting compound (Q) and the template (L) in the solvent (S) while adjusting the pH, and the slurry is subjected to reduced pressure filtration, pressure filtration or centrifugation. Recover solids, preferably 20-1
This is dried under normal pressure or reduced pressure at 50 ° C., preferably for 1 to 100 hours, to obtain a mesoporous substance containing a template.

Template Agent To remove the template agent from the mesoporous material containing polyoxyethylene alkylamine, for example, the following method can be applied.

A) A mesoporous material containing a template agent polyoxyethylene alkylamine, preferably from 300 to 1
200 ° C., more preferably 500-800 ° C., in air, preferably 1-50 hours, more preferably 3-20 hours
Bake for hours. The pressure of the atmosphere is usually normal pressure, but may be a pressurized state.

B) Template Agent A mesoporous substance containing polyoxyethylene alkylamine is mixed with an extraction solvent, and the template agent is extracted with the solvent. The template extracted in the solvent is recovered,
Reused. The extraction solvent may be one having both hydrophilicity and hydrophobicity, and for example, alcohols such as methanol and ethanol, amines, acetone, acetonitrile and the like are preferably used.

[0033]

The polyoxyethylene alkylamine [I] constituting the template according to the present invention has an intermediate property between alkylamine and polyethylene oxide, and is inexpensive and highly safe. This shows higher hydrophilicity than the alkylamine, and the hydrophilicity can be adjusted by the length of the (EtO) _n chain. It also retains the properties of an amine as compared with polyethylene oxide-based ones, and can be operated under mild conditions. The values of the surface area and pore volume of the obtained mesoporous substance are equivalent to those in the case of using a quaternary ammonium salt, and are higher than those in the case of using alkyl polyethylene oxide or polyethylene polypropylene triblock oxide. Show. Further, the amount of the polyoxyethylene alkylamine [I] used may be less than half the amount of the quaternary ammonium salt or the alkylamine, and the material cost can be significantly reduced.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be specifically described with reference to several embodiments of the present invention. However, these examples do not limit the present invention.

Example 1 Synthesis of a Mesoporous Material Containing a Template Agent At room temperature, polyoxyethylene laurylamine (C ₁₂ H
_25- NH- (EtO) ₅ ) (10.1 g, 0.025 mol) was mixed with 135 g (7.49 mol) of water and ethanol.
The mixture was dissolved in 0 g (1.00 mol) of a mixed solvent, and 15.62 g (0.075 mol) of tetraethyl orthosilicate was added thereto. The mixture was stirred at room temperature for 48 hours. Thereafter, the solid content was collected by filtration, washed with water, and heated at 40 ° C. for 6 hours.
After drying for 0 hour, a solid content of 8.84 g was obtained. The _{solids, Hm (C 12 H 25 -NH-} (EtO) 5)
A mesoporous substance having a chemical structure of _0.15 SiO ₂ and containing a template agent from a physical property measurement described later (template-containing DP
S-11).

Example 2 Removal of Molding Agent by Firing 2.34 g of the solid content obtained in Example 1 was fired in air at a temperature of 550 ° C. for 3 hours to obtain an ash content (molding agent-removed DPS-1).
1) 1.18 g was obtained. It has ₂ comprising chemical structure HmSiO.

Estimated from the weight loss, the SiO 2 of Example 1
The yield based on ₂ % by weight was 99%, and 43.4% by weight of the template agent polyoxyethylene laurylamine was incorporated in the solid content.

Example 3 Synthesis of a Mesoporous Material Containing a Template Agent At room temperature, polyoxyethylene laurylamine (C ₁₂ H
_25- NH- (EtO) ₅ ) was obtained by adding 4.04 g (0.01 mol) of water to 268 g (14.9 mol) of water and ethanol.
The mixture was dissolved in 0 g (2.00 mol) of a mixed solvent, and 15.62 g (0.075 mol) of tetraethyl orthosilicate was added thereto. The mixture was stirred at room temperature for 48 hours. Thereafter, the solid content was collected by filtration, washed with water, and heated at 40 ° C. for 6 hours.
After drying for 0 hours, a solid content of 8.19 g was obtained. The _{solids, Hm (C 12 H 25 -NH-} (EtO) 5)
A mesoporous material having a chemical structure of _0.12 SiO ₂ and containing a template agent from the physical property measurement described below (template-containing DP
S-11).

Example 4 Removal of Molding Agent by Firing 2.06 g of the solid content obtained in Example 3 was fired in air at a temperature of 550 ° C. for 3 hours to obtain ash (DPS-1 with removal of molding agent).
1) 1.16 g was obtained. It has ₂ comprising chemical structure HmSiO.

Estimating from the weight loss, the SiO 3 of Example 3
₂ weight yield is 100%, 88.6 wt% of the templating agent polyoxyethylene lauryl amine had been incorporated into the solid.

Measurement of Physical Properties The physical properties of the following items were measured for the products obtained in Examples and Comparative Examples.

A) X-ray diffraction wavelength CuKα = (λ = 1.5418 angstroms)
The diffraction pattern of the product obtained in the above example was measured using a diffractometer equipped with an X-ray light source.

The calculation of the spacing (d) was based on the Bragg equation 2d sin θ = λ.

Each of the products obtained in Examples 1 to 4 showed a clear diffraction peak on the low angle side, confirming that the products had a regular mesostructure. The calculated interplanar spacings were 43.7, 47.0, 44.1, and 42.9 angstroms, respectively.

B) Adsorption isotherm The product obtained in Example 2 (DPS-11 with removal of template)
, The nitrogen adsorption isotherm was measured at 77K. BET
The specific surface area calculated by the method was 1054 m ² / g, the average pore diameter calculated by the BJH method was 40.3 Å, and the pore volume was 1.17 ml / g (P / Po = 0.99).

The product obtained in Example 4 (template removal D
For PS-11), a nitrogen adsorption isotherm was measured at 77K. The measurement results are shown in the graph of FIG. This graph confirmed that the product was a mesoporous material.

The specific surface area calculated by the BET method is 992 m ²
/ G, average pore diameter calculated by the BJH method is 37.1 angstroms, and pore volume is 1.15 ml / g (P / Po =
0.99).

[0048]

According to the present invention, an inexpensive and highly safe polyoxyethylene alkylamine can be used as a template in the synthesis of a mesoporous substance. According to the method of the present invention, a mesoporous substance can be produced at low cost under mild conditions. The mesoporous material according to the present invention has a pore diameter of 20 Å or more, a high surface area and a large pore volume,
It is useful in fields such as material chemistry, catalytic chemistry, surface chemistry, and organic synthetic chemistry.

[Brief description of the drawings]

FIG. 1 is a graph showing an adsorption isotherm of a product obtained in Example 4.

Claims (5)

[Claims] 1. A general formula: R ¹ —NH— (EtO) _n ... [I] (wherein, R ¹ is an alkyl group having 8 to 36 carbon atoms.
(EtO) _n is a polyethylene oxide chain, and n is an integer of 2 to 200. A template for producing a mesoporous substance comprising a polyoxyethylene alkylamine represented by the formula: 2. A method for producing a mesoporous substance, comprising producing a mesoporous substance using the template of claim 1. 3. The method according to claim 1, wherein the compound of the formula (R)¹-NH- (EtO)_n)_r1R² _r2M_m(A_aB_bC_cD_dE_eF _f G_gO_x) [...] [II] (where A is a divalent element, and a is a coefficient of 0 to 1)
You. B is a trivalent element, and b has a coefficient of 0 to 0.67.
You. C is a tetravalent element, and c has a coefficient of 0 to 0.5.
You. D is a pentavalent element, and d is a coefficient of 0 to 0.4.
You. E is a hexavalent element, and e has a coefficient of 0 to 0.33.
You. F is a heptavalent element, and f has a coefficient of 0 to 0.29.
You. G is an octavalent element, and g has a coefficient of 0 to 0.25.
You. O is an oxygen atom, and x is its coefficient 1. However,
All of the coefficients a, b, c, d, e, f and g are
Never be b. M is a hydrogen atom, an alkali metal,
Selected from the group consisting of alkaline earth metals and rare earth metals
M is a coefficient of 0.001-2.
is there. R¹-NH- (EtO)_nIs included in structure [II]
2. The template part according to claim 1, wherein r1 is a coefficient of 0.1.
01 to 1. R²Are the above elements A to G (these are Z
Generic name) and Z-carbon bond or Z-oxygen-carbon bond
Wherein r2 is a coefficient of 0 to 1
is there. ) To produce the template-containing mesoporous material represented by
A method for producing a mesoporous substance, comprising: 4. The method of claim 3, wherein the template agent is removed from the mesoporous material containing the template agent to obtain a general formula: R ² _r2 M _m (A _a B _b C _c D _d E _e F. _f G _g O _x ) [...] [III] (where A is a divalent element, a has a coefficient of 0 to 1. B is a trivalent element, and b is a coefficient of 0. C is a tetravalent element, c has a coefficient of 0 to 0.5, D is a pentavalent element, d has a coefficient of 0 to 0.4, and E is a hexavalent element. E is a coefficient of 0 to 0.33, F is a heptavalent element, f is a coefficient of 0 to 0.29, G is an octavalent element, and g is a coefficient of 0 to 0.39. O is an oxygen atom, and x is a coefficient of 1.
All of the coefficients a, b, c, d, e, f, and g are not simultaneously zero. M is a hydrogen atom, an alkali metal,
M is at least one selected from the group consisting of alkaline earth metals and rare earth metals, and m has a coefficient of 0.001-2. R ² is the above elements A to G (these are collectively referred to as Z)
And an organic group linked by a Z-carbon bond or a Z-oxygen-carbon bond, and r2 has a coefficient of 0 to 1. A method for producing a mesoporous substance, characterized by producing the mesoporous substance represented by the formula (1). 5. A mesoporous substance produced by the method according to claim 2. Description: